1. Field of the Invention
This invention relates to a catheter tube connector, and in particular, but not solely to a catheter tube connector for a suction system used with a tracheostomy or endrotracheal patient ventilation system.
2. Summary of the Prior Art
There are a number of medical procedures that require placement of a tracheostomy or endotracheal tube into the windpipe to deliver air directly into the lungs. A patient who is ventilated in this manner cannot clear secretions collecting in their lungs and airways by themselves. To overcome this problem, a sterile flexible aspirating tube is inserted into the patient via the tracheostomy or endotracheal tube. The aspirating tube is used in conjunction with an external vacuum source to create suction and help clear the secretions. In the method of secretion removal known as the open suction system, the aspirating tube is disposed of immediately after use as it will have become contaminated by the pathogens and bacteria that live in the patient's airway, and once it is removed from the patient's airway the tube will be exposed to atmosphere, with the risk of contaminating caregivers. An alternative to the open suction system is known as the closed suction system, where the aspirating tube is enclosed within a sealed flexible plastic envelope when outside the patient, allowing the aspirating tube to be used several times and then changed either when necessary or after a set period, usually every 24 hours. The closed suction system provides a degree of protection from contaminants for anyone in contact with the patient, such as caregivers and similarly protects the patient from caregivers and the like. Since it was first introduced, various aspects of the closed system have been refined in order to improve the usefulness of the system.
U.S. Pat. No. 4,351,328 discloses a combined tracheostomy ventilator tube and patient aspirating system of the open type. The device disclosed has the disadvantage that the aspirating catheter tube is exposed to the atmosphere before being pushed into the trachea via the tracheostomy tube. The catheter tube also comes into contact with the external parts of the seal as it penetrates through it, allowing it to pick up germs on the external surfaces of the ventilator before depositing these in the patient's lungs. A further disadvantage of this system is that the resistance of the tube passing through and over the seal can be high, and can cause the patient some discomfort as the tracheostomy tube and other fittings are inadvertently moved and twisted in order to overcome this resistance.
U.S. Pat. No. 4,569,344 discloses a combined tracheostomy ventilator tube and patient aspirating system of the closed type. The device disclosed has the disadvantage that the ventilator tube is unsealed when the connector is released in order to carry out routine cleaning or maintenance, or in order to replace the aspirating system, allowing external airborne germs to enter the trachea through the ventilator tube. Also, it is difficult to maintain PEEP (Positive end-expiratory pressure) within the system if the system is not sealed, such as is the case here when the connector is released. If PEEP is not maintained throughout the system, not only can this affect the ventilation of the patient, but in the most common form of tracheal tube layout, an inflated cuff is used to hold and seal the ventilation and aspiration cannula of the tracheostomy tube in place in the patient's windpipe. If PEEP is lost, this cuff can deflate, allowing subglottic fluids that have pooled above the cuff to leak into the patient's lungs. The device disclosed in this specification also has the disadvantage that the end of the catheter tube is fully exposed before connection, and makes contact with exposed portions of the external surfaces of the ventilator as it is pushed through into the trachea, leading to a greater chance of infecting the patient.
U.S. Pat. No. 5,060,646 discloses a similar closed system for ventilation and aspiration. This system has the disadvantage that the aspirating assembly containing the catheter tube cannot be removed for replacement or maintenance without unsealing the ventilating system, malting it difficult to maintain PEEP, and allowing airborne germs to enter the system. Whilst in this case the catheter tube can be inserted into the ventilator without coming into contact with the external surfaces, this can only occur when the ventilator is unsealed, with the previously mentioned disadvantages. Also, removing and connecting the aspirating assembly is via a resistance fitting, and so the patient can experience discomfort from the increased likelihood of twisting and pulling, as outlined above.